I agree REST APIs should be built this way, however I disagree any end user should ever have to think about APIs this way. I think a good SDK should hide most of this complexity away, and no real human should ever have to know the difference between a PUT or a POST. APIs should think more like people; people shouldn't have to think more like APIs.
EDIT: Since I didn't make my case well enough, here's an example. Let's say you want to charge a credit card. Are you doing a `POST /charge`? Or would it be better to say `card.charge(500)`? My point isn't that there shouldn't be a proper REST API below it, but rather that we should offer abstractions so normal semi-technical people can use APIs and don't have to think too much like a computer.
EDIT: Since I didn't make my case well enough, here's an example. Let's say you want to charge a credit card. Are you doing a `POST /charge`? Or would it be better to say `card.charge(500)`? My point isn't that there shouldn't be a proper REST API below it, but rather that we should offer abstractions so normal semi-technical people can use APIs and don't have to think too much like a computer.